Substituted amino-5,6,7,8-tetrahydronaphthyl-oxyacetic acids, processes for their preparation and their use as medicaments

ABSTRACT

Antithrombotic, antiatherosclerotic and antiischaemic compounds of the formula ##STR1## in which R 1  is ##STR2##  or SO 2  R 4 , R 3  is aryl, substituted aryl, heteroaryl, aralkyl or the group ##STR3## R 4  is aryl or substituted aryl, R 2  is OH, alkoxy, phenoxy, benzoxy or NR 5  R 6 , and 
     R 5  and R 6  each independently is hydrogen or alkyl, or 
     one of the radicals R 5  or R 6  is benzyl, 
     and physiologically acceptable salts thereof with mono- and divalent cations.

The present invention relates to newamino-5,6,7,8-tetrahydronaphthyl-oxyacetic acids, processes for theirpreparation and the use of amino-5,6,7,8-tetrahydronaphthyl-oxyaceticacids as medicaments, in particular as antithrombotics,antiatherosclerotics and anti-ischaemic agents.

Thrombosis and arteriosclerotic vascular changes are controlled, aboveall, by the interaction of two metabolites of arachidonic acid, that isto say by thromboxan A₂ (TXA₂) and by prostacyclin (PGI₂). TXA₂ has anaggregating effect on blood platelets, and PGI₂ has an antiaggregatingeffect. Moreover, TXA₂ has a vasoconstrictory effect and PGI₂ avasodilatory effect.

In a number of thrombo-embolic and ischaemic diseases,hyperaggregability of the platelets or an increased platelet consumptionleads to an increased thromboxan synthesis, so that the TXA₂ and PGI₂equilibrium is disturbed. It is therefore desirable for the therapy andprophylaxis of thrombo-embolic and ischaemic diseases for the thromboxaneffect to be inhibited and the protective properties of the PGI₂therefore to be increased.

It has now been found, surprisingly, that certainamino-5,6,7,8-tetrahydronaphthyloxyacetic acids have a specific andpotent antagonistic action in respect of thromboxan A₂.

Thromboxan-antagonistic and platelet aggregation-inhibitingamino-5,6,7,8-tetrahydronaphthyloxyacetic acids of the general formula(I) ##STR4## in which R¹ represents ##STR5## or SO₂ R⁴ wherein

R³ represents aryl, substituted aryl, heteroaryl, aralkyl or the group##STR6## and wherein

R⁴ represents aryl or substituted aryl, and

R² represents OH, alkoxy, phenoxy, benzoxy or

NR⁵ R⁶,

wherein

R⁵ and R⁶ are identical or different and each represents hydrogen oralkyl, or

one of the radicals R⁵ or R⁶ represents benzyl,

and physiologically acceptable salts thereof with mono- or divalentcations have been found.

Compounds of the general formula (I) which are of particular interestare those in which R¹ represents CO--R³ or SO₂ R⁴,

wherein

R³ represents phenyl or naphthyl which optionally carries 1, 2 or 3identical or different substituents from the group comprising halogen,cyano, trifluoromethyl and alkyl with 1 to 4 C atoms,

or represents pyridine, quinoline or aralkyl with 7 to 12 carbon atoms,the aralkyl radical optionally being substituted in the alkyl part byhalogen or hydroxyl and optionally being substituted in the aryl part byhalogen or alkyl with 1 to 4 carbon atoms, or represents the groupCHOH--aryl,

wherein

aryl denotes phenyl or naphthyl which is optionally substituted by 1, 2or 3 radicals from the group comprising halogen, cyano, trifluoromethyland alkyl with 1 to 4 carbon atoms,

R⁴ represents phenyl or naphthyl, which optionally carry 1, 2 or 3identical or different substituents from the group comprising halogen,cyano, trifluoromethyl and alkyl with 1 to 4 C atoms, and

R² represents hydroxyl, phenoxy, benzoxy or alkoxy with 1 to 4 carbonatoms, or represents the group NR⁵ R⁶,

wherein

R⁵ and R⁶ are identical or different and each represent hydrogen oralkyl with 1 to 4 carbon atoms, or

one of the radicals R⁵ or R⁶ represents benzyl,

and physiologically acceptable salts thereof with mono- or divalentcations.

Fluorine and chlorine are of particular interest from the group ofhalogens.

The new amino-5,6,7,8-tetrahydronaphthalene-oxyacetic acid derivativesof the formula (I) can exist both as enantiomers and enantiomer pairs,and if a further asymmetry is present in one of the radicals, asdiastereomer pairs.

Preferred processes for preparing optical isomers are: makingdiastereomeric salts of amines of formula II with optical active acids,separation of the diastereomeric salts by crystallisation and followingisolation of the free optical active amines, or via the preparation ofoptical active imines of ketones of formula V with (+) or (-)α-methylbenzylamines, subsequent hydration of the imine-double-bond andremoval of the benzylmoiety by further hydration.

It has furthermore been found that theamino-5,6,7,8-tetrahydronaphthyl-oxyacetic acids I are obtained by aprocess in which the amines of the general formula (II) ##STR7## inwhich R² has the abovementioned meaning, are reacted with carboxylicacids of the general formula R³ --COOH, R³ having the abovementionedmeaning, or activated derivatives thereof, such as acid chlorides oranhydrides or activated esters, or with sulphonic acids of the generalformula R⁴ SO₃ H, R⁴ having the above-mentioned meaning, or activatedderivatives thereof, such as acid chlorides or activated esters, in amanner which is known per se. In the case where R² =OH, the reaction isfollowed by hydrolysis to give the free carboxylic acids.

It has furthermore been found that theamino-5,6,7,8-tetrahydronaphthyl-oxyacetic acid derivatives I are alsoobtained by a process in which the phenols of the general formula (III)##STR8## in which R¹ has the abovementioned meaning, are reacted withacetic acid derivatives of the general formula (IV)

    X--CH.sub.2 --COR.sup.2                                    (IV)

in which

X denotes a leaving group, such as, for example, Cl, Br, I, SO₂ CH₃ or##STR9## and R² has the abovementioned meaning,

in the presence of acid-binding agents.

This process variant is particularly suitable if R¹ contains no sulphuratom.

In the case where R² ≠OH, the reaction is followed by hydrolysis to givethe free carboxylic acids.

The aminotetralin-oxyacetic acid derivatives II are obtained from thecorresponding tetralones V ##STR10## wherein R₇ is a keto group and

R² has the abovementioned meaning,

by reductive amination by a process analogous to those known from theliterature (for example J. Am. Chem. Soc. 93, 2897 (1971); Rylander,"Catalytic Hydrogenation", pages 291-303, Academic Press, Inc., NewYork, 1967; and Org.-Reactions 4, 174-255 (1948)).

The tetralones V are obtained by alkylation of the correspondinghydroxytetralins VI ##STR11## in which R₇ has the abovementionedmeaning, with acetic acid derivatives of the general formula X--CH₂--CO₂ R² (IV), in which X and R² have the above-mentioned meaning, byprocesses which are known from the literature (for example Patai "TheChemistry of the Hydroxyl group", part 1, pages 454-466, IntersciencePublishers, New York, 1971; and Tetrahedron 30, 1379 (1974)).

The hydroxytetralones VI are known from the literature in some cases(for example J. Org. Chem. 14, page 366 (1949)), and some of them can beprepared from the known methoxytetralones XI by ether cleavage by aprocess analogous to those known from the literature (for example Org.Syntheses, Volume 51, page 109; and J. Chem. Soc. 1855 (1949)).

The aminotetralin-oxyacetic acid derivatives II can likewise be obtainedby a process in which the acetamides VII ##STR12## in which R² has theabovementioned meaning, are subjected to acid or basic hydrolysis in aknown manner. VII can be obtained in a manner analogous to that alreadydescribed for III→II, by alkylation of the OH group of the phenols VIII##STR13## with the acetic acid derivatives IV. The acetylatedamino-hydroxytetralins VIII are obtained from the correspondingamino-hydroxytetralins IX ##STR14## or salts thereof with inorganicacids, by acetylation of the amino and hydroxyl function and subsequentselective hydrolysis of the ester by generally known processes.

The phenols of the general formula III can also be prepared from theamnohydroxytetralins IX by processes analogous to those known from theliterature (for example Chem. Ber. 103, 788 (1970)). This procedure isparticularly suitable if R¹ does not contain a sulphur atom. The phenolsof the general formula III can also be prepared from compounds of thegeneral formula XII ##STR15## by ether cleavage by known processes, forexample by reaction with BBr₃.

The amino-hydroxy-tetralones IX are known in some cases (for example J.Med. Chem. 22, 1469 (1979)), or they can be prepared via themethoxy-aminotetralins X ##STR16## or salts thereof with inorganicacids, by reductive amination from the corresponding knownmethoxy-tetralones XI ##STR17## in which R⁷ has the abovementionedmeaning, by processes analogous to known processes.

Examples which may be mentioned of the methoxytetralones XI used asstarting substances are: 5-methoxy-1-tetralone, 5-methoxy-2-tetralone,6-methoxy-1-tetralone, 6-methoxy-2-tetralone and 6-methoxy-3-tetralone.

The syntheses sequences can be summarized in reaction scheme as follows,starting from the methoxy-tetralones XI: ##STR18## wherein R¹, R² and R⁷have the abovementioned meanings.

In the case where ##STR19## R³ having the abovementioned meaning, theend products I are obtained by a process in which the amines of thegeneral formula II are reacted with the corresponding carboxylic acidsR² --COOH or activated derivatives thereof, for example acid chlorides,acid anhydrides or activated esters.

If the activated derivatives are employed, the reaction isadvantageously carried out in the presence of an acid-binding agent,such as, for example, alkali metal hydroxides or carbonates or alkalineearth metal hydroxides or carbonates or organic bases, such astriethylamine, pyridine or N-ethylmorpholine.

Suitable solvents, depending on the nature of the carboxylix acidderivative employed, are organic solvents, such as, for example,methylene chloride, chloroform, ethyl acetate, tetrahydrofuran, ether ordimethylformamide, or protic solvents, such as, for example, water,methanol or ethanol.

The reaction temperature is between 0° and 100° C., preferably between0° and 30° C.

If the free carboxylic acids R³ --COOH are employed, the reaction can becarried out, for example, in the manner described in Chem. Ber. 103, 788(1970).

In the case where R¹ =SO₂ R⁴, R⁴ having the abovementioned meaning, theend products I are obtained by reacting the amines of the generalformula II with the corresponding sulphonic acids R⁴ SO₃ H or activatedderivatives thereof, such as, for example, sulphonic acid chlorides,sulphonic acid anhydrides or sulphonic acid esters, in the presence ofan acid-binding agent, such as, for example, alkali metal hydroxides orcarbonates or alkaline earth metal hydroxides or carbonates or organicbases, such as, for example, triethylamine, pyridine orN-ethylmorpholine.

Suitable diluents are the same as those which have already beenmentioned for the reaction with the carboxylic acid derviatives. If R²in the compounds of the general formula I represents O-alkyl or NR⁵ R⁶,the reaction can be followed by hydrolysis under basic or acidconditions in a generally known manner.

The compounds of the general formula I are also obtained by the processvariant from the phenols III in which R¹ has the abovementioned meaningby a procedure in which the phenols III are alkylated with acetic acidderivatives of the general formula IV in which R² and X have theabovementioned meaning.

The alkylation is advantageously carried out in the presence of anacid-binding agent, such as, for example, alkali metal hydroxides orcarbonates or alkaline earth metal hydroxides or carbonates or organicbases, such as, for example, triethylamine, pyridine ordiazabicycloundecane, in organic solvents, such as acetone, butanone,dimethylformamide, dimethylsulphoxide, ethanol, dioxane or toluene.

It is frequently advantageous to add an alkali metal halide, such as,for example, sodium iodide or potassium iodide, and a water-bindingagent, such as a 3 Å molecular sieve.

The reaction temperature is between 50° and 150°, preferably between 50°and 80° C., depending on the solvent.

Examples which may be mentioned of the compounds of the general formulaI are:5-(4-fluorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid, 5-phenylsulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(4-Methylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(3,4-dichlorobenzoylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(3,4-dichlorobenzoylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,5-(4-fluorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid, 5-phenylsulphonylamino-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,6-(3,4-dichlorobenzoylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,6-(4-fluorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,6-(4-chlorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,6-(4-fluorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,7-(4-fluorphenylsulphonyl)amino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,7-(4-chlorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,7-(4-chlorophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(4-methylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,6-(4-methylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,5-(4-trifluoromethylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,5-(4-cyanophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,6-(4-trifluoromethylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid,5-(4-cyanophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(4-trifluormethylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,6-(4-cyanophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,ε-(4-trifluormethylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,6-(4-methylphenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,6-(4-cyanophenylsulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid.

Possible formulation forms are the customary galenical administrationforms, for example creams, tablets, pills, capsules, suppositories,emulsions and infusion and injection solutions. These formulation formsare prepared by methods which are known per se, using customaryauxiliaries and excipients.

The medicaments thus prepared are used as required, for example bylocal, parenteral or oral administration.

Formulations which contain the compounds according to the invention inconcentrations of about 0.1 to 10% by weight are particularly suitable.Aqueous solutions, which if appropriate are buffered to a pH of 6 to 8,are particularly preferred.

The dosage of the substitutedamino-5,6,7,8-tetrahydro-naphthyl-oxyacetic acid derivatives in themedicaments according to the invention is preferably in a range from0.05 to 100 mg/kg, in particular 0.1 to 20 mg/kg of body weight.

The substituted amino-5,6,7,8-tetrahydronaphthyloxyacetic acidscontained in the medicaments according to the invention are used asthromboxan antagonists and platelet aggregation-inhibitors forpreventing and treating thromboses, thromboembolisms and ischaemicdiseases, and as antiasthmatics and as antiallergics.

METHOD Platelet aggregation inhibition in vitro

Blood from healthy donors who have taken no medicament for at least 14days is used for the in vitro determination of the plateletaggregation-inhibiting action. The blood is taken up in 3.8% strengthsodium citrate solution. Platelet-rich plasma (PRP) is obtained bycentrifugation at 150 g at room temperature for 20 minutes(Jurgens/Beller: Klinische Methoden der Blutgerinnungsanalyse (ClinicalMethods of Blood Coagulation Analysis); Thieme Verlag, Stuttgart 1959).The platelet aggregation is determined by the turbidometric method(Born, G. V. R.: J. Physiol. 162, 67, 1962) in an aggregometer at 37° C.For this, PRP is incubated with the test substance at 37° C. and theaggregation is then induced by addition of a collagen suspension. Forthe in vitro experiments, the minimum effective active compoundconcentration (MEC) which inhibits platelet aggregation in thecorresponding PRP samples is quoted.

Platelet aggregation inhibition ex vivo

For the ex vivo investigations, the active substance is administeredorally to the animals in a tylose suspension. After 90 minutes, theanimals are exsanguinated and the PRP is obtained by means ofcentrifugation. The aggregation inhibition is measured analogously tothe method described for the in vitro experiments; however, there is nopreincubation of the samples.

The results of the collagen-induced platelet aggregation of someexamples are shown in the table.

    ______________________________________                                                    Inhibition of platelet aggregation                                            (in vitro)                                                        Example No. Limit concentration [mg/l]                                        ______________________________________                                        54          0.3-0.1                                                           55          3-1                                                               56          0.3-0.1                                                           57          0.3-0.1                                                           58           0.1-0.03                                                         63          10-3                                                              66          10-3                                                              ______________________________________                                    

EXAMPLE 1 5-Amino-1-methoxy-5,6,7,8-tetrahydro-naphthalene hydrochloride

50 mmol of 5-methoxy-1-tetralone, 0.5 mol of NH₄ OAc and 35 mmol ofNaBH₃ CN are stirred in 150 ml of absolute MeOH at room temperature for24 hours. The mixture is acidified to pH 2 with concentrated HCl andevaporated, the residue is taken up in 50 ml of H₂ O and the mixture isextracted by shaking 2-3×with ether. Any precipitates which arise arefiltered off and combined with the H₂ O phase. The H₂ O phase is broughtto pH 10 with solid KOH, saturated with NaCl and extracted by shaking3×with ethyl acetate. After drying with Na₂ SO₄, the organic phase isevaporated, the residue is dissolved in ether and the product isprecipitated as the hydrochloride by passing the HCl. Yield: 79%;melting point: 250° C.

The following compounds were prepared in an analogous manner:

EXAMPLE 2 5-Amino-2-methoxy-5,6,7,8-tetrahydro-naphthalene hydrochloride

Yield: 79% of theory; melting point: 262° C.

EXAMPLE 3 6-Amino-1-methoxy-5,6,7,8-tetrahydro-naphthalene hydrochloride

Yield: 62% of theory; melting point: 258° C.

EXAMPLE 4 6-Amino-2-methoxy-5,6,7,8-tetrahydro-naphthalene hydrochloride

Yield: 42% of theory; melting point: 239° C.

EXAMPLE 5 7-Amino-1-methoxy-5,6,7,8-tetrahydro-naphthalene hydrochloride

Yield: 61.4% of theory; melting point: 97° C.

EXAMPLE 6 5-Amino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene hydrobromide

0.15 mol of 5-amino-1-methoxy-5,6,7,8-tetrahydronaphthalenehydrochloride is heated at a bath temperature of 125° C. in 75 ml ofaqueous 48% strength HBr for 3 hours. The mixture is evaporated, theresidue is dissolved in a little ethanol and the products areprecipitated as the hydrobromides by addition of ether. Yield: 80% oftheory; melting point: 152° C.

The following compounds were prepared in an analogous manner:

EXAMPLE 7 5-Amino-2-hydroxy-5,6,7,8-tetrahydro-naphthalene hydrobromide

Yield: 18% of theory

EXAMPLE 8 6-Amino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene hydrobromide

Yield: 72% of theory; melting point: 248° C.

EXAMPLE 9 6-Amino-2-hydroxy-5,6,7,8-tetrahydro-naphthalene hydrobromide

Yield: 84% of theory; melting point: 275° C.

EXAMPLE 107-Benzenesulphonylamino-1-methoxy-5,6,7,8-tetra-hydronaphthalene

10.25 g (56 mmol) of 7-amino-1-methoxy-5,6,7,8-tetra-hydro-naphthaleneare dissolved in 100 ml of analytical grade pyridine, 10.6 g (60 mmol)of benzenesulphonyl chloride are added dropwise at room temperature,exothermic reaction, subsequently stir at room temperature for 1 hour,reaction mixture concentrated in vacuo, residue purified over a silicagel column (K₆₀, mobile phase toluol:acetone 10:1).

Yield: 10.8 g (61% of theory).

Rf value (K₆₀ film) 0.75 (mobile phase: toluene:ethanol:triethylamine10:3:1).

EXAMPLE 11 5-Benzoylamino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene

50 mmol of benzoic acid and 50 mmol of 1-hydroxybenzotriazole (HOBT) aretaken in 200 ml of absolute tetrahydrofuran at 0° C. 55 mmol ofdicyclohexylcarbodiimide (DCC) are added under N₂ and the mixture isstirred at 0° C. for 1 hour and then at room temperature for 1 hour. 50mmol of 5-amino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene hydrobromideand 50 mmol of triethylamine are added to this solution and the mixtureis stirred at room temperature for 6 hours.

The mixture is filtered, the residue is rinsed thoroughly withtetrahydrofuran and the filtrate is evaporated. The residue is taken upin ethyl acetate and washed once with saturated NaHCO₃ solution, oncewith 1N HCl, once with saturated NaHCO₃ solution and once with saturatedNaCl solution. After drying over Na₂ SO₄, the mixture is evaporated, theresidue is dissolved in a little acetone, and after 1 hour in arefrigerator the residual dicyclohexylurea which has precipitated out isfiltered off. The filtrate is evaporated and the residue isrecrystallized from acetone by addition of petroleum ether.

Yield: 53% of theory; melting point: 160° C.

The compounds summarized in Table 1 were prepared in an analogousmanner:

                                      TABLE 1                                     __________________________________________________________________________     ##STR20##                                                                                                   Melting point (in the case of                                            % yield                                                                            crystals) or wave number of                    Substitution positions    (in % of                                                                           the amide band in the IR                       Example                                                                            OH  NHCOR  Radical R theory)                                                                            spectrum in the case of oils                   __________________________________________________________________________    12   1   5                                                                                     ##STR21##                                                                              76   1655 cm.sup.-1                                 13   1   5                                                                                     ##STR22##                                                                              83   230° C.                                 14   2   5                                                                                     ##STR23##                                                                              31   1660 cm.sup.-1                                 15   2   5                                                                                     ##STR24##                                                                              27   1650 cm.sup.-1                                 16   1   6                                                                                     ##STR25##                                                                              60   198° C.                                 17   1   6                                                                                     ##STR26##                                                                              77   1660 cm.sup.-1                                 18   1   6                                                                                     ##STR27##                                                                              58   232-33° C.                              19   2   6                                                                                     ##STR28##                                                                              82   173-75° C.                              20   2   6                                                                                     ##STR29##                                                                              58   1640 cm.sup.-1                                 21   2   6                                                                                     ##STR30##                                                                              85   230° C.                                 __________________________________________________________________________

EXAMPLE 22 5-Acetylamino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene

50 mmol of 5-amino-1-hydroxy-5,6,7,8-tetrahydronaphthalene are stirredin a solution of 200 mmol of acetic anhydride and 200 mmol oftriethylamine, to which a spatula-tip of dimethylaminopyridine has beenadded, for 2 hours. The mixture is filtered, the residue is rinsedthoroughly with tetrahydrofuran and the filtrate is evaporated. Theresidue is taken up in ethyl acetate and the mixture is washed with 1NHCl, saturated NaHCO₃, 1N, HCl, saturated NaHCO₃ and saturated NaClsolution, dried over Na₂ SO₄ and evaporated. The bis-acetate whichremains is dissolved in 100 ml of MeOH and the solution is then addeddropwise to 100 ml of 1N KOH at room temperature. The mixture is stirredat an internal temperature of 50° C. for 2 hours and acidified withconcentrated HCl and the MeOH is stripped off. The acid aqueous phase isextracted by shaking 2 to 3 times with ethyl acetate and the combinedorganic phases are dried with Na₂ SO₄ and evaporated. The residue isrecrystallized from ethyl acetate.

Yield: 92% of theory ¹ H-NMR (CD₃ OD): δ=1.95 (s, 3H).

The following compounds were prepared in an analogous manner:

EXAMPLE 23 5-Acetylamino-2-hydroxy-5,6,7,8-tetrahydro-naphthalene

Yield: 33% of theory ¹ H-NMR (CD₃ OD): δ=2.0 (s, 3H).

EXAMPLE 24 6-Acetylamino-1-hydroxy-5,6,7,8-tetrahydro-naphthalene

Yield: 81% of theory ¹ H-NMR (CD₃ OD): δ=1.95 (s, 3H).

EXAMPLE 25 6-Acetylamino-2-hydroxy-5,6,7,8-tetrahydro-naphthalene

Yield: 82% of theory ¹ H-NMR (CD₃ OD): δ=2.0 (s, 3H).

EXAMPLE 26 Methyl5-benzoylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetate

50 mmol of 5-benzoylamino-1-hyroxy-5,6,7,8-tetrahydro-naphthalene and100 ml of anhydrous potassium potassium carbonate are stirred at 50° C.in 100 ml of absolute dimethylformamide for 20 minutes. A solution of 60mmol of methyl chloroacetate and 25 mmol of potassium iodide in 25 mldimethylformamide is added dropwise and the mixture is stirred at 50° C.for 6 to 8 hours. It is filtered under the influence of heat, theresidue is rinsed thoroughly with ethyl acetate and the filtrate isevaporated. The residue is stirred in a mixture of 10% strength NaOH andethyl acetate or tetrahydrofuran for 10 minutes. The ethyl acetate phaseis extracted by shaking once with 10% strength NaOH, dried over Na₂ SO₄and evaporated. The residue is recrystallized from ethyl acetate.

Yield: 86% of theory; melting point: 242° C.

The examples of Table 2 were prepared in an analogous manner:

                                      TABLE 2                                     __________________________________________________________________________     ##STR31##                                                                                                       Melting point in the case                                                     of crystals of wave number                                               Yield %                                                                            of the amide band in the                   Example                                                                            Substitution positions   (in % of                                                                           IR spectrum in the case of                 No.  OCH.sub.2 CO.sub.2 CH.sub.3                                                           NHCOR  Radical R theory)                                                                            oils                                       __________________________________________________________________________    27   1       5      CH.sub.3  92   196° C.                             28   1       5                                                                                     ##STR32##                                                                              72   115° C.                             29   1       5                                                                                     ##STR33##                                                                              52   1665 cm.sup.-1                             30   2       5      CH.sub.3  33   165° C.                             31   2       5                                                                                     ##STR34##                                                                              91   149-150°  C.                        32   2       5                                                                                     ##STR35##                                                                              45   1665 cm.sup.-1                             33   1       6      CH.sub.3  81   120° C.                             34   1       6                                                                                     ##STR36##                                                                              69   125-27° C.                          35   1       6                                                                                     ##STR37##                                                                              21   1670 cm.sup.-1                             36   1       6                                                                                     ##STR38##                                                                              75   1665 cm.sup.-1                             37   2       6      CH.sub.3  82   110-113° C.                         38   2       6                                                                                     ##STR39##                                                                              47   130° C.                             39   2       6                                                                                     ##STR40##                                                                              14   1665 cm.sup.-1                             40   2       6                                                                                     ##STR41##                                                                              44   1660 cm.sup.-1                             __________________________________________________________________________

EXAMPLE 41 6-Amino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetic acid

20 mmol of methyl6-acetylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetate are refluxed in300 ml of 2N HCl for 24 hours. The product precipitates on cooling to 0°C.

Yield: 89% of theory; melting point: 271°-73° C.

The following compounds were prepared in an analogous manner:

EXAMPLE 42 5-Amino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetic acid

Yield: 17% of theory ¹ H-NMR (CD₃ OD): δ=4.65 (s, 2H).

EXAMPLE 43 5-Amino-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetic acid

Yield: 14% of theory ¹ H-NMR (CD₃ OD): δ=4.65 (s, 2H).

EXAMPLE 44 6-Amino-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetic acid

Yield: 71% of theory; melting point: 305° C.

EXAMPLE 45 Methyl 7,8-tetrahydro-5(6H)-naphthalenon-1-yl-oxyacetate

0.5 mol of 5-hydroxy-1-tetralone is refluxed together with 0.6 mol ofmethyl chloroacetate, 0.25 mol of potassium iodide and 1 mol ofpotassium carbonate in 1 l of butanone for 6 hours. The mixture isfiltered with suction, the residue is rinsed thoroughly with acetone andthe filtrate is evaporated. The residue is taken up in 500 ml ofmethylene chloride and the mixture is washed three times with 0.5N NaOHand once with water, dried over sodium sulphate and evaporated. Theresidue is distilled using a bulb tube. (Boiling point: 250° C./0.3 mm)or crystallized from ligroin (melting point: 84°-85° C.). Yield: 83% oftheory

The following compounds are prepared in an analogous manner:

EXAMPLE 46 Methyl 7,8-tetrahydro-5(6H)-naphthalenon-2-yl-oxyacetate

Yield: 76% of theory; melting point: 116°-118° C.

EXAMPLE 47 5-Amino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetamide

50 mmol of methyl 7,8-tetrahydro-5(6H)-naphthalenon-1-yl-oxyacetate arereacted in 100 ml of methanol and 50 ml of NH₃ for 5 hours at 110° C.under 100 bar of hydrogen over 5 g of Raney nickel. The mixture isfiltered hot with suction, the filtrate is evaporated and the residue isrecrystallized from toluene.

Yield: 68% of theory; melting point: 133°-140° C.

EXAMPLE 48 5-Amino-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetamide

Yield: 89% of theory ¹ H-NMR (CD₃ OD): δ=4.45 (s, 2H).

EXAMPLE 495-(4-Chloro-benzenesulphonylamino)-5,6,7,8-tetrahydronaphth-2-yl-oxyacetamide

33 mmol of p-chlorosulphonyl chloride in 20 ml of absolutetetrahydrofuran are added dropwise to 30 mmol of5-amino-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetamide and 60 mmol oftriethylamine in 80 ml of absolute tetrahydrofuran at room temperature.The mixture is subsequently stirred at room temperature for 6 hours andfiltered and 30 ml of ether are added. The organic phase is washed with1N HCl, saturated NaHCO₃ solution and saturated NaCl solution, driedover Na₂ SO₄ and evaporated.

Yield: 58% of theory; ¹ H-NMR (d₆ -DMSO): δ=4.35 (s, 2H); melting point:203°-5° C.

EXAMPLE 505-(4-Chloro-benzenesulphonylamino)-5,6,7,8-tetrahydronaphth-1-yl-oxyacetamide

Yield: 52% of theory; melting point: 205°-208° C. ¹ H-NMR (d₆ -DMSO):δ=4.45 (s, 2H).

EXAMPLE 517-Benzenesulphonylamino-5,6,7,8-tetrahydro-1-hydroxynaphthalene

9.6 g (30 mmol) of7-benzenesulphonylamino-1-methoxy-5,6,7,8-tetrahydronaphthalene aredissolved in 150 ml of analytical grade CH₂ Cl₂, 40 ml of 1 molar (40mmol) of boron tribromide solution are added dropwise at roomtemperature, the reaction mixture is subsequently stirred at roomtemperature for 1 hour and poured onto ice-water containing a littleL-(+)-tartaric acid, the CH₂ Cl₂ is separated off and the mixture isdried over MgSO₄ and concentrated in vacuo, crystalline residue.

Yield: 5.7 g (62.7% of theory).

Melting point: 152°-154° C.

EXAMPLE 52 Ethyl7-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-1-yl-oxyacetate

5.3 g (17.5 mmol) of7-benzenesulphonylamino-5,6,7,8-tetrahydro-1-hydroxy-naphthalene and2.76 g (20 mmol) of ground K₂ CO₃ are stirred in 100 ml of analyticalgrade dimethylformamide, 3.35 g (20 mmol) of ethyl bromoacetate areadded dropwise at room temperature the reaction mixture is subsequentlystirred at room temperature for 1 hour and filtered and the motherliquor is concentrated in vacuo.

Yield: 6.6 g (97% of theory).

Rf value: K₆₀ film 0.45 (mobile phase toluene:acetone 4:1).

EXAMPLE 537-Benzenesulphonylamino-5,6,7,8-tetrahydronaphth-1-yl-oxyacetic acid

3.89 g (10 mmol) of ethyl7-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-1-yl-oxyacetate and 840mg (15 mmol) of KOH are stirred in 50 ml of C₂ H₅ OH and 20 ml of H₂ Oat room temperature for 20 hours. The solvent is stripped off, theresidue is partitioned between H₂ O and CH₂ Cl₂, the mixture is broughtto pH 4.5 with 10% strength HCl and extracted twice with CH₂ Cl₂, theorganic phases are dried over MgSO₄ and concentrated in vacuo, theresidue is triturated with ether and the crystals are filtered off withsuction and dried.

Yield: 1.8 g (49.7% of theory).

Melting point: 205° C.

EXAMPLE 546-Benzenesulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetic acid

10 mmol of 6-amino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetic acid and 20mmol of benzenesulphonyl chloride are warmed at 80° C. in 40 ml of 10%strength NaOH for 2 hours. The mixture is then acidified withconcentrated HCl and the milky suspension is extracted by shaking twicewith ethyl acetate. The combined ethyl acetate phases are rapidlyextracted by shaking with 10% strength NaOH (product precipitates out ofthe ethyl acetate), the NaOH phase is acidified with concentrated HCland extracted by shaking twice with ethyl acetate and the extract isdried over Na₂ SO₄ and evaporated. The residue is boiled up in ethylacetate and the mixture is filtered. The product crystallizes out after2-3 hours in a refrigerator.

Yield 63% of theory ¹ H-NMR (NaOD): δ=4.55 (s, 2H), melting point: 175°C.

The following compounds were prepared analogously:

EXAMPLE 556-(4-Chlorobenzenesulphonylamino)-5,6,7,8-tetrahydronaphth-1-yl-oxyaceticacid

Yield: 67% of theory; melting point; 248° C.

EXAMPLE 566-Benzenesulphonylamino-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetic acid

Yield: 54% of theory ¹ H-NMR (NaOD): δ=4.5 (s, 2H).

EXAMPLE 575-(4-Chlorobenzenesulphonylamino)-5,6,7,8-tetrahydronaphth-2-yl-oxyaceticacid

10 mmol of5-(4-chlorobenzenesulphonylamino)-5,6,7,8-tetrahydro-naphth-2-yl-oxyacetamideare heated under reflux in 12 ml of 2N KOH and 40 ml of MeOH for 6hours. The methanol is stripped off, 30 ml of 1N KOH are added and themixture is extracted by shaking twice with CH₂ Cl₂. The H₂ O phase isbrough to pH 2 with concentrated HCl and the precipitates is filteredoff and dried thoroughly.

Yield: 71% of theory.

¹ H-NMR (d₆ -DMSO): δ=4.6 (s, 2H).

The following compounds are prepared analogously:

EXAMPLE 585-(4-Chlorobenzenesulphonylamino)-5,6,7,8-tetrahydronaphth-1-yl-oxyaceticacid

Yield: 66% of theory; melting point: 210° C. (ethyl acetate/petroleumether).

EXAMPLE 595-(4-Fluorobenzenesulphonylamino)-5,6,7,8-tetrahydronaphth-1-yl-oxyaceticacid

Yield: 68% of theory; melting point.

EXAMPLE 60 5-Benzoylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetic acid

50 mmol of methyl5-benzoylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyacetate are stirred in60 ml of 1N NaOH and 120 ml of MeOH at room temperature for 6 hours. Themethanol is stripped off, the NaOH solution is extracted by shaking withethyl acetate and the extract is then acidified with 10% strength HClsolution. The acid solution is extracted by shaking 3 times with ethylacetate or tetrahydrofuran, the extract is dried over Na₂ SO₄ andevaporated and the residue is dried under a high vacuum.

Yield: 94% of theory; IR: 1745 cm⁻¹ (CO₂ H).

Further examples which were prepared in an analogous manner aresummarized in Table 3:

                                      TABLE 3                                     __________________________________________________________________________     ##STR42##                                                                                                 Yield %                                                                            Wave number of the                          Example                                                                            Substitution positions  (in % of                                                                           carbonyl band in the                        No.  OCH.sub.2 CO.sub.2 H                                                                 NHCOR  Radical R theory)                                                                            IR spectrum                                 __________________________________________________________________________    61   1      5                                                                                     ##STR43##                                                                              91   1735 cm.sup.-1                              62   1      5                                                                                     ##STR44##                                                                              87   1730 cm.sup.-1                              63   2      5                                                                                     ##STR45##                                                                              90   1755 cm.sup.-1                              64   2      5                                                                                     ##STR46##                                                                              92   1725 cm.sup.-1                              65   1      6                                                                                     ##STR47##                                                                              96   1745 cm.sup.-1                              66   1      6                                                                                     ##STR48##                                                                              94   1740 cm.sup.-1                              67   1      6                                                                                     ##STR49##                                                                              89   1730 cm.sup.-1                              68   2      6                                                                                     ##STR50##                                                                              95   1725 cm.sup.-1                              69   2      6                                                                                     ##STR51##                                                                              95   1725 cm.sup.-1                              70   2      6                                                                                     ##STR52##                                                                              89   1725 cm.sup.-1 (m.p. 211°            __________________________________________________________________________                                      C.)                                     

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

What is claimed is:
 1. An amino-5,6,7,8-tetrahydronaphthyl-oxyaceticacid of the formula ##STR53## in which R⁴ is phenyl or naphthyl whichoptionally carries 1, 2 or 3 substitutents independently selected fromthe group consisting of halogen, cyano, trifluoromethyl and alkyl with 1to 4 C atoms,R² is hydroxyl, phenoxy, benzoxy or alkoxy with 1 to 4carbon atoms, or is NR⁵ R⁶, and R⁵ and R⁶ each independently is hydrogenor alkyl with 1 to 4 carbom atoms, or one of the radicals R⁵ or R⁶ isbenzyl,or a physiologically acceptable salt thereof with a mono- ordivalent cation.
 2. A compound or salt according to claim 1, in whichhalogen is fluorine or chlorine.
 3. A compound according to claim 1,wherein such compound is6-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-1-yl-oxyacetic acid ofthe formula ##STR54## or a physiologically acceptable salt thereof witha mono- or divalent cation.
 4. A compound according to claim 1, whereinsuch compound is6-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid of the formula ##STR55## or a physiologically acceptable saltthereof with a mono- or divalent cation.
 5. A compound according toclaim 1, wherein such compound is6-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-2-yl-oxyacetic acid ofthe formula ##STR56## or a physiologically acceptable salt thereof witha mono- or divalent cation.
 6. A compound according to claim 1, whereinsuch compound is5-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid of the formula ##STR57## or a physiologically acceptable saltthereof with a mono- or divalent cation.
 7. A compound according toclaim 1, wherein such compound is5-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid of the formula ##STR58## or a physiologically acceptable saltthereof with a mono- or divalent cation.
 8. A compound according toclaim 1 wherein such compound is5-(4-Fluorobenzenesulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid of the formula ##STR59## or a physiologically acceptable saltthereof with a mono- or divalent cation.
 9. A composition for inhibitingaggregation of blood platelets comprising an amount effective thereforof a compound or salt according to claim 1 and a pharmacologicallyacceptable diluent.
 10. A unit dose of a composition according to claim8 in the form of a tablet, capsule or ampule.
 11. A method of inhibitingaggregation of blood platelets in a patient in need thereof whichcomprises administering to such patient an amount effective therefor ofa compound or salt thereof according to claim
 1. 12. The methodaccording to claim 11, wherein such compoundis6-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-1-yl-oxyacetic,6-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid, 6-benzenesulphonylamino-5,6,7,8-tetrahydronaphth-2-yl-oxyacetic,5-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-2-yl-oxyaceticacid or5-(4-chlorobenzenesulphonylamino-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,5-(4-fluorobenzenesulphonylamino)-5,6,7,8-tetrahydro-naphth-1-yl-oxyaceticacid,or a physiologically acceptable salt thereof with a mono- ordivalent cation.